The present invention relates to a holding device, and in particular to a holding device as used in machining operations. More particularly, the present invention relates to a holding device which can firmly hold delicate parts without damaging them while preventing movement or tilt of the parts during machining operations. In addition, the holding device that this invention relates to can easily be made from a prefabricated composite bar produced for this purpose.
Machine parts are typically formed with automatic equipment that operates at dangerous speeds and power. The operating forces which are present in this equipment and which are transferred to parts being formed make it impossible to hold these parts unaided while work is in progress. It is common to find vices and other clamping mechanisms in machine shops for holding parts as they are processed.
Most vices, however, include two flat walls between which parts are held. Therefore, vices are most effective when holding parts that include opposing parallel flat surfaces. Many standard clamping mechanisms include jaws designed to hold parts that do not have opposing parallel flat surfaces, however the range of shapes that can be securely held by these standard devices is limited.
It is known to form a holding device that can securely hold parts with odd shapes. For example, Morgan U.S. Pat. No. 3,599,961 shows a holding device formed by bonding a first rigid plate to a pad of resilient material such as neoprene, bonding a second rigid plate to the opposite side of the pad so that there is slight relative movement between the plates, cutting the second rigid plate in half to form opposing jaws for gripping, then forming a cutout in the opposing jaws to match the shape of the part to be held.
The machining equipment in machine shops is typically expensive and workers are typically paid an hourly rate, so it is important to maximize the productivity of the workers and the equipment. If the equipment is broken or is not producing product for some other reason, then the machine shop's capacity is impaired and it must either purchase more equipment than would otherwise be required or sell less product. One problem that reduces the run time of this equipment is set-up time. Each time a machine table load of parts is worked and completed, the machine must be shut down so that the completed parts can be removed from the table and additional parts can be loaded. If bulky clamping devices are employed for holding parts for this operation, fewer parts can be loaded onto the table and fewer parts can be worked on between set-ups. As the number of parts that may be loaded onto the table decreases, the necessary set-up time increases, reducing the run time and thus the capacity of the machine shop equipment.
For the foregoing reasons, there is a need for an improved compact holding device that can securely hold parts with irregular shapes, that can securely hold fragile parts without damaging them, and that can be readily produced in most machine shops.